Wood-grinding machine for paper-pulp



(No model.)

B. F. PERKINS. WOOD GRINDING MACHINE FOR PAPER PULP. No. 243,965.

ATTORNEYS.

Patented July 5, 1881..

WITNESSES: W

UNITED STATES PATENT OFFIcE.

BENJAMIN F. PERKINS, OF BRISTOL, NEW HAMPSHIRE.

'WOOD-GRINDING MACHINE FOR PAPER-PULP.

SPECIFICATION forming part of Letters Patent No. 243,965, dated July 5, 1881,

7 Application filed May 31, 1881. (No model.)

To all whom it may concern Be it known that I, BENJAMIN F. PERKINS, of Bristol, in the county of Grafton and State of New Hampshire, have invented a new and useful Improvement in Wood-Grinding Machines for Paper-Pulp, of which the following is a full, clear, and exact description.

My improvements relate to the class of woodgrinding machine using revolving stones, to which the wood is pressed by feeding devices. I make use of a bevel-edge stone set horizontally with the smaller side downward, and combine with it feed mechanism at opposite sides, so that in operation the step of the stonespindle is relieved from undue pressure, the pulp leaves the stone readily, and at the same time the weight of the stone is utilized to aid the grinding. The feed is a screw-feed, and is provided with adjustments to compensate for wear of the stone, for which purpose, also, the spindle of the stone is provided with an adjustable step, all as hereinafter described and claimed.

In the accompanying drawings, Figure l is a sectional plan view of a grinder containing the improvements, and Fig. 2 is a sectional side view of the same.

Similar letters of reference indicate correspondin g parts.

A is the stone, either natural or artificial, fixed on a vertical spindle, a, that is provided with a drawing-pulley, 1). Stone will either be on wheel-shaft or be driven by gear from wheel-shaft under the stone.

B is the curb around the stone, and O G are the feed-boxes connected with the curb at opposite sides of the stone, and located tangentially thereto.

The stone A is formed with its edge bev eled at any suitable angle, so as to form an overhanging grinding-surface that can be adjusted by vertical movement of the spindle. The step of the spindle is upon a screw, 0, that is fitted in a bridge, (I, so that by turning the screw the spindle and stone are raised and lowered.

The feed-boxes each consist of a fixed box or trunk, e, and an inner loose box or pocket, f, fitting snugly, an d having its forward ends'beveled to it-the surface of stone A. Afeed-screw, 9, passes through the end of the boxes e f,-and

carries a follower, 9, within the box f. On this screw g, between fixed standards h h, is a pulley, 2', formed as or carrying a nut for engaging the screw.

Screws k k, tapped in the end of box 0 and bearing on the end of the inner box or pocket, f, serve to retain the inner ends of the pocket against the stone, and allow adjustment for wear of the stone in addition to the vertical adjustment allowed by the step-screw c.

In operation the blocks of wood are to be set in the box f with the grain of the wood perpendicular, so that the stone shall act across the grain. The grinding-edge being beveled, the cut is made diagonally across the grain, with the effect to produce a superior quality of fiber. Power is to be applied to revolve the nut-pulley t, and the screw thus moved endwise to press the wood continuously forward. The feed-pressure at opposite sides has the effect to lift the stone, thus relieving the step of the greater part of the weight and utilizing such weight in the Work of grinding.

The curb B is made with a section or portion, Z, between the two feed-boxes, hinged or removable, so as to be opened or removed to give access to the stone for sharpening without removing the curb.

There will he usually four feed-boxes, and between them pipes supplying water to the beveled surface of the stone will be fitted. These pipes should supply water in such quantity and force as to wash off the pulp before it reaches the next pocket after grinding, thus preventing a regrind, which blackens the pulp.

The pulley 41 may have its hub formed with a small pulley for receiving a reverse belt. This belt is run from a large driving-pulley on reversed counter-shaft, and a quick reverse movement of the screw thus obtained, when it is required to refill the pockets.

For the proper operation of the machine it is essential that the wood be placed in the pockets, as mentioned, with the grain perpendicular, or as nearly so as may be. The machine is devised to act on the fibers when so placed, and will then give the most satisfactory results.

Having thus described my invention, Iclaim as new and desire to secure by Letters Patent- 1. In wood-grinding machines, the combina tion of beveled-edge stone A, fixed on a vertical shaft, and four feed-boxes O, fixed at opposite sides of the stone, and provided with force-feed mechanism, substantially as shown and described.

2. The vertical spindle a, provided with an adjustable step, the bevel-faced stone A, and horizontal feed-boxes 0, combined for operation substantially as shown and described.

3. In wood-grinding machines, the adjustable box or pocket f, in combination with the fixed box 0, feed-screw g, and stone A, substantially as and for the purpose set forth.

4. The combination of screw g, nut i, fixed box 0, loose box f, adjusting-screws 7c, and bev- 15 eled stone A, substantially as shown and described, for operation as set forth.

BENJAMIN FRANKLIN PERKINS. 

